Improvement in artificial legs



UNITED STATES *PATENT OFFICE.

IMPROVEMENT INv ARTIFICIAL LEGS.

Specification forming part of Letters Patent No. 49,528, dated August22, 1865.

To all 'whom t may concern:

Be it known that I, GEORGE B. J EWETT, of Salem,in the county of Essexand State of Massachusetts, have invented a new and useful Improvementin Artiiicial Legs; and I do hereby declare the same to be fullydescribed in the following specification and represented in theaccompanying drawings, of which- Figure l is a side elevation, Fig. 2 avertical and longitudinal section, and Fig. 3 arear elevation, of anartilicial leg provided with my invention.

Hitherto it has been deemed very difficult, if not impossible,to makeaduly-proportioned artiticial leg suitable for what is termed a longthigh-stump7-that is, one in which the amputation has been madeimmediately above or close to the knee-joint--for to make room for theparts composing the knee-joint of the artiiicial leg it became necessaryto so construct the limb that the knee thereof ,would project beyond thenatural knee of the wearer while in a sitting position, the sameimparting to the person the appearance of having a want ofcorrespondence between thelengths ofthose part-s of his legs which arelocated above his knees. To obviate this difficulty has been one of .themost important desiderata in the manufacture of artificial legs, and isaccomplished by my inp vention,.which also admits of the lower leg beingbent far back into an acute angle with the thigh, whereby a personwearing one of my artiticial legs is enabled to kneel therewith intonatural postures.

In the drawings, A denotes the thigh-socket frame 'as composed in partof four metallic bars, a a a a, arranged at equal distances asun der,and projecting upward from a knee block or piece, b, which issemicircular, or nearly so,

on its upper surface, and is formed with a-ilat base, c, and in otherrespects as shown in the drawings. This base is to rest and bear on acushion or layer of felt, d, lixed on the upper end ofthe lowerleg-column B. The bars a a a a are extended into a stift'leather socket,e, which receivesthestump-cushipnf Alongsideofthe back part ofthekneeframe there extends upward a hanger, g, which should be firmlyfastened to the knee-piece or the metallic frame A, or both, and is torise above the knee-piece and be arranged between and hin ged to twostruts or posts, h h, which project upward from the leg part B in manneras shown in the drawings. The back bar a of the series ot' bars a a a ais between the two struts. I

For formingthe connection of the hanger and the struts a screw-pin, D,is employed, it being passed through one ot the struts and the head ofthe hanger and screwed into the other strut. y

of the knee-piece b and extends down infront thereof'. This elastic bandserves to straighten the limb or bring the knee-piece into bearing onthe cushion on the top of the leg-column.

With the above construction of theknee-joint there will be ample roomover it'and in the socketforthelongestthigh-stump withoutcausing theknee, when the wearer is in a sitting position, to project beyond hisnatural knee.

My invention renders the leg equally appli-` cable to short thigh-stulnps, with which the leg can be used and worn with great comfort andfacility. The successful treatment ot this latter class of cases dependsupon particulars which eminently exist in my improvement, and whichrender the leg easily worn and operated by a short thigh-stump.

With myimprovement not only can the wearer of the leg bend the knee atmore than a right angle, so as to enable him to kneel in naturalpostures, but he is enabled,when sitting, to draw the leg backunderneath the thigh as far as may be desirable.

I claimy 1. The combination and arrangement of the hanger g and the twostruts or posts h It with the thigh-socket frame A and the leg bar oreol- I umn B. Y

2. The combination and arrangement ot' the knee piece or block b withthe thigh-socket frame, the hanger g, and the two struts h h.

3. The arrangement of the cushion d and the ilat base c, or itsequivalent, with the'column B,

the thigh-socket frame A,\the hanger g, and

the struts h h, the whole being substantially as specified.

GEO. B. JEWETT.

Witnesses y JAMES A. GILLIss, THos. F. HUNT.

